Pa Ad By ex 
Mazopus KEpLert, Newb. (p. 180). 
Fries. 1-3. Teeth, all natural size. 
Berea shale, Berea, Ohio. 
HETERACANTHUS POLITUS, Newb. (p. 66). 
4,5. Summit and base of spine, natural size. 
48, Portion of anterior surface enlarged to show sinuous furrows. 
Hamilton limestone, Milwaukee, Wis. 
SANDALODUS CRASSUS, N. & W. (p. 204). 
6. Complete tooth, showing posterior produced angle. 
7. Tooth, usual form. 
8. Tooth, showing crown much worn by use. 
All natural size. Saint Louis limestone, Saint Louis, Mo. 
CLADODUS CONCINNUS, Newb. (p. 170). 
9,10. Teeth of average size, posterior face; Fig. 10 showing central cone much worn. 
Cleveland shale, Lorain County, Ohio. 
HARPACANTHUS FIMBRIATUS, Stock. (p. 203). 
11. Spine. 
Saint Louis limestone, Alton, Ill. 
118, Spine, from drawing by Dr. R. H. Traquair. 
12 
Lower Carboniferous, Scotland. 
PHYSONEMUS STELLATUS, Newb. (p. 200). 
. Spine, side view, natural size. 
Saint Louis limestone, Greencastle, Ind. 
272 a 
